Axially adjustable steering shaft assembly with ball spline

Abstract

A steering shaft assembly for a vehicle uses a ball spline as a slip member. In general, the slip member includes an outer race member, an inner race member, and a pair of end return members. The outer race member includes one or more grooves or recesses, each groove forming an outer race. The inner race member includes a corresponding number of grooves and inner bores to form an outer race track and inner race tracks, respectively. Each outer race and corresponding outer race track form an outer ball recirculating track for transmitting torque through the recirculating ball bearings. Each inner race track forms an inner ball recirculating track for providing a circumferential path for the ball bearings. In one embodiment, the inner race member and end return members are generally cylindrical in cross sectional shape that is disposed within the outer race member. The outer race member, inner race member and end return member can be any desired cross sectional shape. For example, the inner race member and return end members can include one or more projections extending outwardly to the outer race member. The slip member can be used a steering shaft assembly that is in production by forming grooves in the outer race member to form the outer races and inserting ball recirculating track members within a corresponding number of slots formed in an existing yoke tube.